Process for recovering a spacecraft first stage

ABSTRACT

The process comprises the steps of: 1) launching the vehicle from the launch site using the first stage booster rocket engine system; 2) separating the at least one upper stage from the first stage booster; 3) terminating operation of the first booster stage rocket engine system; 4) turning the first stage booster back toward the launch site using the aerodynamic flight control system; 5) operating the first stage booster rocket engine system to boost the first stage booster to an altitude sufficient to allow non-powered flight back to the launch side; and 6) landing the first stage booster at the launch site.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to multi-stage vehicles for launching payloadsinto space; and, in particular, to a process for recovery of arecoverable first stage of the launch vehicle.

2. Description of Related Art

In the past, expendable multistage rockets were used to boost payloadsinto space (earth orbit or beyond). However, boosters are expendable.This is especially true if they are man rated. Thus reusable boostershave been designed and the reusable space shuttle is in operation.

The Kistler-K1 Reusable Launch Vehicle or Space Shuttle have a return tolaunch site (RTLS) maneuvers. The toss back maneuver that the KistlerK-1 performs to return to the launch site uses rocket propulsion torotate the velocity vector of the K-1 such that the resulting ballistictrajectory terminates back at the launch site. Likewise, the SpaceShuttle RTLS uses rocket propulsion to slow the vehicle and rotate itsvelocity vector so that the resulting trajectory places the Shuttlewithin gliding range of the landing site. In both of the precedingexamples rocket propulsion is used to reverse the heading of the vehicleso that additional rocket propulsion can be used to return the vehicleto the launch site. Neither of these approaches minimizes energyconsumption.

U.S. Pat. No. 6,450,452 Fly Back Booster by R. B. Spenser and U.S. Pat.No. 6,612,522 Flyback Booster With Removable Rocket Propulsion Module byB. Aldrin, et al. both use jet engines mounted on the booster to powerthe booster back to the launch site. However, the use of a separatepropulsion system adds weight and significantly raises the cost of thebooster.

Thus, it is a primary object of the invention to provide a procedure forrecovering the first stage of a multistage spacecraft booster.

It is another primary object of the invention to provide a procedure forrecovering the first stage of a multistage spacecraft booster that makesuse of the existing propulsion system used at lift off.

It is a further object of the invention to provide It is another primaryobject of the invention to provide a procedure for recovering the firststage of a multistage spacecraft booster that makes use of the existingpropulsion system used at lift off that returns the first stage to thepoint of launch.

SUMMARY OF THE INVENTION

The invention is a process for returning the first stage booster of alaunch vehicle having at least one upper stage, the first stage boosterhaving a rocket engine system and aerodynamic flight control system, tothe launch site, the process comprising the steps of: 1) launching thevehicle from the launch site using the first stage booster rocket enginesystem; 2) separating the at least one upper stage from the first stagebooster; 3) terminating operation of the first booster stage rocketengine system; 4) turning the first stage booster back toward the launchsite using the aerodynamic flight control system; 5) operating the firststage booster rocket engine system to boost the first stage booster toan altitude sufficient to allow non-powered flight back to the launchside; and 5) landing the first stage booster at the launch site.

By using this process, no secondary propulsion system, such as jetengines, are required. Furthermore, the use of only aerodynamic flightcontrols to turn the aircraft back toward the landing site requires lessfuel to remain on board the first stage booster. Finally, the firststage booster will land with a minimum of residual fuel on board.

The novel features which are believed to be characteristic of theinvention, both as to its organization and method of operation, togetherwith further objects and advantages thereof, will be better understoodfrom the following description in connection with the accompanyingdrawings in which the presently preferred embodiment of the invention isillustrated by way of example. It is to be expressly understood,however, that the drawings are for purposes of illustration anddescription only and are not intended as a definition of the limits ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a two stage launch vehicle.

FIG. 2 is a graph of the launch and return profile for the first stagebooster.

FIG. 3 is a graph of altitude versus time for launch and return of thefirst stage booster.

FIG. 4 is a graph of the landing profile of the first stage booster.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, the launch vehicle, generally indicated by numeral10, includes a first stage booster 12 and a second stage 14 designed toreach orbit. Note that the second stage could incorporate additionalstages (not shown). The first stage booster 12 includes wings 16 rudderassemblies 18 and a rocket propulsion system 20. Thus the first stagebooster 12 would be unmanned and controlled from the launch site 22. Thesecond stage 14 includes its own rocket propulsion system 15.

FIG. 2, is plot of the trajectory of the vehicle 10 and to FIG. 3, is aplot of altitude versus time. The vehicle 10 would take off from thelaunch site 22 using the propulsion system 20. The launch vehicle 10climbs to an altitude indicated by numeral 23 and then costs to analtitude indicated by numeral 24 where the booster 12 propulsion system20 is turned off, and the second stage 14 is released and its propulsionsystem 15 is ignited and accelerates upward to space. The booster 12 nowdescends and begins to turn back to the launch site 22. Considerablealtitude is lost in this process. When the booster 12 is turned in thedirection of the takeoff side 22, the propulsion system 20 is reignitedat point 26. The booster 12 climbs under power to an altitude indicatedby numeral 27. Being essentially empty of fuel, it coasts up to analtitude indicated by numeral 28 much higher than the stage separationpoint 24. At this point the booster 12 makes a ballistic reentry andglides to the launch site 22.

Note that the second stage separation occurs at around 180,000 feet andthe maximum altitude reached by the booster 12 when returning to thelaunch site 22 is around 270,000 feet. Of course these altitudes willvary from mission to mission and individual vehicle designs. FIG. 4illustrates the booster's spiral approach to the landing site 22. Asillustrated the landing site is at Cape Canaveral, Fla.

Thus it can be seen that the process provides for a most efficientflight profile, providing optimum fuel usage and maximum flexibility inachieving return to the launch site.

While the invention has been described with reference to a particularembodiment, it should be understood that the embodiment is merelyillustrative as there are numerous variations and modifications whichmay be made by those skilled in the art. Thus, the invention is to beconstrued as being limited only by the spirit and scope of the appendedclaims.

INDUSTRIAL APPLICABILITY

The invention has applicability to spacecraft booster manufacturingindustry.

1. A process for returning the first stage booster of a launch vehiclehaving at least one upper stage, the first stage booster, having arocket propulsion system and aerodynamic flight control system, to thelaunch site, the process comprising the steps of: launching the vehiclefrom the launch site using the first stage booster rocket propulsionsystem; separating the at least one upper stage from the first stagebooster; terminating operation of the first booster stage rocketpropulsion system; turning the first stage booster back toward thelaunch site using the aerodynamic flight control system; operating thefirst stage booster rocket propulsion system to boost the first stagebooster to an altitude sufficient to allow non-powered flight back tothe launch side; and landing the first stage booster at the launch site.2. A process for returning the first stage booster of a launch vehiclehaving at least one upper stage, the first stage booster, having arocket propulsion system and aerodynamic flight control system, to thelaunch site, the process comprising the steps of: providing the firststage booster with fuel in excess of that required to booster the atleast one upper stage to its separation point from the first stagebooster; launching the vehicle from the launch site using the firststage booster rocket propulsion system; separating the at least oneupper stage from the first stage booster; terminating operation of thefirst booster stage rocket propulsion system, turning the first stagebooster back toward the launch site using the aerodynamic flight controlsystem; operating the first stage booster rocket propulsion system usingthe fuel in excess of that required to boost the first stage booster toan altitude sufficient to allow non-powered flight back to the launchside; and landing the first stage booster at the launch site.